I have some "real" main protagonists from various scripts. One of them I happen to know is my cousin's full name. It wasn't intentional though. I just started writing the script and had a first name for a few weeks, and when it came time for a last name, I decided on the most boring everyday name I could think of: Brown. And only a few weeks after that did I realize that THAT first name and THAT last name together are my cousin's name. (And, according to Google, an astronaught's name.)
Another is a photographer in Colorado.
Another is a platinum-level benefactor of an art museum in California.
Another is a Broadway performer from the 1920's.
Another doesn't exist.
Then I have some fantasy main protags. These are supposed to be totally made up names comepletely from my brain and should have nothing to do with anything here on God's green Earth. If I google the fanatsy names and even THEY turn up, then it's back to the drawing board. Here's what I came up with:
1) My fantasy bad guy is found on a Spanish language web site headquartered in Chile. It's a web site that sells domain names. And THAT name is currently available.
2) My fantasy good guy doesn't exist anywhere on the web.
3) None of my other supporting fantasy characters exist anywhere on the web.
(I guess my fantasy names are safe then.

)